<!DOCTYPE html>
<title>CSS Anchor Positioning: position-area positioning inside grid</title>
<link rel="help" href="https://drafts.csswg.org/css-anchor-position/#position-area">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<!--
    Grid:

          100      100      100      100
      +--------+--------+--------+--------+
      |        |        |        |        |
  100 |        |        |        |        |
      |        |        |        |        |
      +--------+--------+--------+--------+
      |        |        |XXXXXXXX|XXXXXXXX|
  100 |        |        |XXXXXXXX|XXXXXXXX|
      |        |        |XXXXXXXX|XXXXXXXX|
      +--------+--------+--------+--------+
      |        |        |XXXXXXXX|XXXXXXXX|
  100 |        |        |XXXXXXXX|XXXXXXXX|
      |        |        |XXXXXXXX|XXXXXXXX|
      +--------+--------+--------+--------+
      |        |        |        |        |
  100 |        |        |        |        |
      |        |        |        |        |
      +--------+--------+--------+--------+


    Inset regions:

          100        150           150
      +--------+-------------+------------+
      |        |             |            |
      |        |             |            |
  150 |        |             |            |
      |        |             |            |
      |        |             |            |
      +--------+-------------+------------+
      |        |             |            |
   75 |        |             |            |
      |        |             |            |
      +--------+-------------+------------+
      |        |             |            |
      |        |             |            |
  175 |        |             |            |
      |        |             |            |
      |        |             |            |
      +--------+-------------+------------+

  -->

<style>
  #container {
    display: grid;
    grid: 1fr 1fr 1fr 1fr / 1fr 1fr 1fr 1fr;
    position: relative;
    width: 400px;
    height: 400px;
  }

  #anchor {
    position: absolute;
    left: 100px;
    top: 150px;
    width: 150px;
    height: 75px;
    anchor-name: --anchor;
  }

  #anchored {
    grid-row-start: 2;
    grid-row-end: span 2;
    grid-column-start: 3;
    grid-column-end: auto;
    position: absolute;
    align-self: stretch;
    justify-self: stretch;
    position-anchor: --anchor;
  }
</style>

<div id="container">
  <div id="anchor"></div>
  <div id="anchored"></div>
</div>
<script>
  function test_position_area(position_area, insets, expected_offsets) {
    anchored.style.positionArea = position_area;
    for (const [prop, value] of Object.entries(insets)) {
      anchored.style[prop] = value;
    }

    test(() => {
      assert_equals(anchored.offsetLeft, expected_offsets.left, "Check expected offsetLeft");
      assert_equals(anchored.offsetTop, expected_offsets.top, "Check expected offsetTop");
      assert_equals(anchored.offsetWidth, expected_offsets.width, "Check expected offsetWidth");
      assert_equals(anchored.offsetHeight, expected_offsets.height, "Check expected offsetHeight");
    }, "Offsets for position-area: " + position_area + " and insets: " + JSON.stringify(insets));
  }

  test_position_area("span-bottom span-left", {left:"auto", right:"auto", top:"auto", bottom:"auto"},
                  {left:200, top:150, width:50, height:150});

  test_position_area("span-bottom span-left", {left:"10px", right:"10px", top:"10px", bottom:"10px"},
                  {left:210, top:160, width:30, height:130});
</script>
